Improvement in telephones



E; BERLINER,

Telephone.

Patented Jan. 15,1878.

lir l/flli a til INVENTOR WITNESSES cf. A- M NPEIERS,FHOTO-LITMOGRAPHER, WASHINGTON D C.

. the transmitter.

UNITED STATES PATENT UFFICE.

EMILE BERLINER, OF WASHINGTON, DISTRICT OF COLUMBIA.

IMPROVEMENT IN TELEPHONES.

Specification forming part of Letters Patent No. 199,141, dated January15,1878; application filed October 16, 1877.

To all whom it may concern:

Be it known that I, EMILE BERLINER, of Washington, District of Columbia,have invented certain new and useful Improvements in ElectricalTelephony, of which the following is a specification:

These improvements shall be applied, in such instances where itisnecessary to increase the effect of an electric current on atelephonereceiver, by connecting the main line on which the transmitteris situated with a local-battery circuit on which the receiver issituated. They also refer to a certain multiplication of a former deviceof the telephone itself, as herein more fully specified.

In an application for Letters Patent made by me June 4, 1877, I haveshown how sound may be transmitted and reproduced by means of avibratory metal or carbon plate in contact with a metal or carbon pin.The transmission was made by either breaking the contact or byalternately weakening and strengthening the same at each vibration ofsound affecting the plate. The reproduction of the sound was effected bypermitting such a current thus consisting of electric waves to passthrough a similar receiving-instrument, consisting also of a metal orcarbon plate in a vibratory position in contact with a metal or carbonpin. As shown in the said application, each electric wave passing overthe point of contact would cause a recoiling of the plate from the pin.Thereby an air-wave would be produced, and, as the electric waves wouldfollow one after the other in exact accordance with the transmittingsound-waves, the air waves or vibrations produced by thereceiving-instrument, occurring at the same rate and measure, would,therefore, reproduce the same tone that affected Since then I have foundthat when'sound is transmitted by varying the intensity of the currentwithout interrupting the samenamely, by merely weakening orstrengthening the contact at each vibration, and thereby the current-theeffect on the receiving-instrument is not very strong, andparticularlyat long distances the effect is but feeble, and requires some attentionto be audible. I have therefore constructed an apparatus, together witha combination of currents, which will materially assist to remedy thedeficiency mentionedfirst, by having not one but several points ofcontact with one and the same plate, or a modification of such a deviceby which several contacts are afiected simultaneously and, secondly, byusing akind of telephonic relay or transfer in connection with alocal-battery circuit. This is shown in the drawings, as follows:

In Drawing No. 1, R is a telephone, consisting of a metal or carbonplate, A, in contact with the metal or carbon pins or screws K K, andmounted on the box or tube 0, while the screws are held in position bythe insulatingbar m. T is a telephone-transmitter, consisting of avibratory plate, A, in contact with the pin K. ated within a separatebattery-circuit, and each circuit passes through the primary coil of oneof the two induction apparatus 1 2 and 1 2, while the secondary currentsor lines of both have been combined into one closed circuit, as shown bythe double arrows. The consequence of this combination is not only thatany changes of the intensity in one battery-circuit will produce asimilar change in the other, but by this any sound affecting theinstrument T will be reproduced by the instrument It, or vice versa, andif the two are separated by a distance which would materially weaken thestrength of a galvanic current, the local battery will supply some ofthe lost force. This phenomenon is partly explained by theiron cores DD. These cores, being electromagnetic, strive toward an equilibrium oftheir electro-magnetic force, and any change herein caused by avariation of the respective battery-current will cause a similarmagnetic change in the other core, which change will again affect theother battery-current by induction.

This combination can be used with great advantage in submarine-cabletelegraphy, or other kind where it is advisable to send messages bymerely modifying the electrical condition of the cable or main line. Forthis purpose an inductorium is placed on each shorestation. One pole ofeither secondary coil is connected to the cable, while the other pole ofthe same circuit is grounded on its respective shore. The primary coilof each inductorium is connected at short circuit to a local battery,

Each of these instruments is situwhich circuit passes through atelephone. By merely suddenly weakening, strengthening, or interruptingthe primary current on one shore a metallic-sounding tick is heard fromthe telephone on the other side of the cable, and a tick again onrestoring the circuit to its former condition. Using, therefore, aclosed Morse key as interrupter or modifier of the primary current,common telegraphing can be carried on, which, being oral or audible, ismuch preferable to the present method of optic signs. The tick producedis not a reproduced sound, I01 sound was not transmitted, but is merelyone air-wave, acccompanied by an internal vibration of the molecules ofthe plate caused by the action of one electric wave passing over thepoint of contact. A feature of this combination is also that, whenlettingthe secondary circuit pass through a human body, no shock is feltwhen interrupting the primary of one inductorium, provided the twoprimary currents are of equal strength. If one, however, is strongerthan the other, a shock is felt depending in strength upon thedifference in strength of both primary currents.

In combination with this the number of contactpins may be increased upto a certain extent, in order to multiply the effect this instrumentshall produce.

In Figure II is shown a modification of the telephone, in which there isthe box or tube 0, closed by the two vibratory plates A A, in contactwith the pins K K, both contacts becoming affected simultaneously byelectrical Waves passing over them. The effect is simiiar to thatdescribed in the telephones, Fig. I.

The combination of the three circuits may, at course, be applied toother kinds of telephones than those described herein, and is alsosubject to changes of form, place, or arrangenent to each other, becausethere are many :orms of induction apparatus on the same prinziple; andthe main telegraph-line may be either )ne of the primary circuits or thesecondary zircuit common to both.

It is but natural that in certain cases it is preferable to use only onecontact-pin in the same instrument, according to what effect shall beproduced. I onlymention echo-songs, when to heighten the effect,sometimes one and again several contacts may be employed.

I do not claim, broadly, the combination, in the telegraphic circuit, oftwo or more tympans, a resonant box, and one or more circuit-closers toeach tympan, when such an arrangementis used for a transmitter of soundonly 5 but What I do claim is- 1. A telephonic receiving-instrumentconsisting of a vibratory plate of metal or carbon, forming one pole orend of a galvanic current, arranged in contact with several metal orcarbon pins, which together form the opposite pole of the sam e'current,for reproducing sound.

2. A telephonic receiving-instrument consisting of two metal or carbonplates in a vibratory position, each in contact with a metal or carbonpin, arranged in such a manner that both contacts are affectedsimultaneously by the same electric waves.

3. A combination of two induction 'appa ratus withtwo separatebattery-circuits, one of each passing through one of the primary coils,the secondaries of which are combined into one closed circuit with theironcores, for

the purpose described.

4. A mode of transformin g waves of induced or tensional electricityinto sound by permitting them to act by induction upon a continuedgalvanic current, which passes through a vibratory medium, forming onepole, and being in contact with the opposite one of the said samegalvanic current.

5. The telephonic receiving-instrument situated within a continuedgalvanic circuit, in which undulations are produced by the inductiveundulatory currents of another electric circuit.

EMILE BERLINER.

